The present invention relates, in general, to a constant velocity universal joint of the tripod type for installation in driveshafts of motor vehicles, and especially to a displacement joint for use in a constant velocity universal joint. More particularly, the present invention is directed to a configuration of roller bearing assemblies used in constant velocity universal joints.
Typically, a constant-velocity universal joint of a tripod type is arranged in an outer joint part, normally bell-shaped, and includes a tripod mounted in fixed rotative engagement to a driveshaft and having a tripod spider provided with symmetrically distributed spherical tripod arms. Each tripod arm is supported on roller bearing assemblies for slideably guiding the joint in recesses of the outer joint part. Each roller bearing assembly includes a bearing shell which is supported by the spherical arm of the tripod spider. In constant velocity universal joints of this type, the components within the joint for executing the angular and translational motions of the joint are separated from another. At a transitional movement, as encountered during operation of the driveshaft at a diffraction angle, the sliding friction is replaced by a combined sliding and rolling friction or rolling friction. At the same time, the axial force required for implementing a shift of the joint decreases.
German Pat. No. DE 34 40 105 C2 describes a constant velocity universal joint having a roller bearing assembly including a bearing shell which is supported on the spherical arm of the tripod spider via a ball socket. The rolling members are configured as needles and disposed between the bearing shell and a track provided in the outer joint part. Contacting rolling members are placed in a cage which has collars of half-round configuration along the longitudinal sides, whereby terminal conical projections of the rolling members engage in the collars. A positioning device in the form of a H-shaped needle spring is arranged in parallel relationship to the plane of the rolling members and disposed between the bearing shell and a terminal end of the rolling member cage for acting upon the cage and thus for centering the rolling members in relation to the bearing shell. The positioning device is provided to support the bearing shell independently from the diffraction angle of the driveshaft over the entire width of the rolling members so as to establish a substantially constant load or surface pressure between these components.
This conventional constant velocity universal joint has many shortcomings. The respective conical end surfaces of the rolling members cause increased manufacturing costs and their installation is complicated. Moreover, the neighboring, contacting rolling members, configured as needles, in the cage cause increased friction as a result of the fully needled arrangement, accompanied by an increased axial force which also adversely affects the noise development.
It would therefore be desirable and advantageous to provide an improved displacement joint for a constant velocity universal joint, which obviates prior art shortcomings and which is so configured as to realize an optimum support of the bearing shell on rolling members while still being easy to install and allowing the use of conventional rolling members.